From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 20 Dec 2019 17:34:14 +0000 (+0100)
Subject: backport: re PR c++/92732 (Bit-field of scoped enumeration type cannot be initialized)
X-Git-Tag: releases/gcc-9.3.0~288
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d4a646993d1fdc6b660c9f403b83fa2ae385c613;p=thirdparty%2Fgcc.git

backport: re PR c++/92732 (Bit-field of scoped enumeration type cannot be initialized)

	Backported from mainline
	2019-12-03  Jakub Jelinek  <jakub@redhat.com>

	PR c++/92732
	* typeck2.c (digest_nsdmi_init): For bitfields, use
	DECL_BIT_FIELD_TYPE instead of TREE_TYPE.

	* g++.dg/cpp2a/bitfield3.C: Don't expect narrowing conversion
	warnings.
	* g++.dg/cpp2a/bitfield4.C: New test.

From-SVN: r279665
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index b727db680e7e..7b09a30d0ab2 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -3,6 +3,10 @@
 	Backported from mainline
 	2019-12-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/92732
+	* typeck2.c (digest_nsdmi_init): For bitfields, use
+	DECL_BIT_FIELD_TYPE instead of TREE_TYPE.
+
 	PR c++/92695
 	* constexpr.c (cxx_bind_parameters_in_call): For virtual calls,
 	adjust the first argument to point to the derived object rather
diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c
index bdb98f844350..b406368a5d6e 100644
--- a/gcc/cp/typeck2.c
+++ b/gcc/cp/typeck2.c
@@ -1291,6 +1291,8 @@ digest_nsdmi_init (tree decl, tree init, tsubst_flags_t complain)
   gcc_assert (TREE_CODE (decl) == FIELD_DECL);
 
   tree type = TREE_TYPE (decl);
+  if (DECL_BIT_FIELD_TYPE (decl))
+    type = DECL_BIT_FIELD_TYPE (decl);
   int flags = LOOKUP_IMPLICIT;
   if (DIRECT_LIST_INIT_P (init))
     {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b8f1c54098db..a116f43b4538 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -3,6 +3,11 @@
 	Backported from mainline
 	2019-12-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/92732
+	* g++.dg/cpp2a/bitfield3.C: Don't expect narrowing conversion
+	warnings.
+	* g++.dg/cpp2a/bitfield4.C: New test.
+
 	PR c++/92695
 	* g++.dg/cpp2a/constexpr-virtual14.C: New test.
 
diff --git a/gcc/testsuite/g++.dg/cpp2a/bitfield3.C b/gcc/testsuite/g++.dg/cpp2a/bitfield3.C
index 511c8894703f..5482da490e2b 100644
--- a/gcc/testsuite/g++.dg/cpp2a/bitfield3.C
+++ b/gcc/testsuite/g++.dg/cpp2a/bitfield3.C
@@ -15,11 +15,9 @@ const int b = 0;
 struct S {
   int c : 5 = 2 * a;			// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
   int d : 6 { c + a };			// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
-					// { dg-warning "narrowing conversion of" "" { target *-*-* } .-1 }
   int e : true ? 7 : a = 3;
   int f : (true ? 8 : b) = d + a;	// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
   int g : (true ? 9 : b) { f + a };	// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
-					// { dg-warning "narrowing conversion of" "" { target *-*-* } .-1 }
   int h : 1 || new int { 0 };
   int i = g + a;
 };
@@ -28,11 +26,9 @@ template <bool V, int W>
 struct U {
   int j : W = 3 * a;			// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
   int k : W { j + a };			// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
-					// { dg-warning "narrowing conversion of" "" { target *-*-* } .-1 }
   int l : V ? 7 : a = 3;
   int m : (V ? W : b) = k + a;		// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
   int n : (V ? W : b) { m + a };	// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
-					// { dg-warning "narrowing conversion of" "" { target *-*-* } .-1 }
   int o : 1 || new int { 0 };
   int p = n + a;
 };
diff --git a/gcc/testsuite/g++.dg/cpp2a/bitfield4.C b/gcc/testsuite/g++.dg/cpp2a/bitfield4.C
new file mode 100644
index 000000000000..bbfa86cbb9e2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/bitfield4.C
@@ -0,0 +1,12 @@
+// PR c++/92732
+// { dg-do compile { target c++17 } }
+// { dg-options "" }
+
+enum class byte : unsigned char { };
+using uint8_t = unsigned char;
+
+struct T
+{
+  byte a : 2 = byte{0};	// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
+  uint8_t b : 2 = 0;	// { dg-warning "default member initializers for bit-fields only available with" "" { target c++17_down } }
+} t;